Lecture 5: Anatomy of Thigh and Stifle Flashcards
what is the portion of the pelvic limb between the pelvic girdle and stifle
thigh
how is movement of the thigh achieved
muscles that move the coxofemoral joint
3 components/joints of the stifle
femoro-tibial
femoro-patellar
proximal tibio-fibular
what connects all 3 joints of the stifle
single capsule
what kind of bone is the patella
sesamoid bone
sesamoid bone definition
floating bone that grows within a tendon
location of patella
within tendon of quadriceps femoris
extra sesamoid bone in canine stifle
femoro-fabellar joint
fabellae
sesamoid bone in proximal heads of gastrocnemius
what kind of synovial joint is the stifle
complex = joint capsule + articular cartilage + discs/menisci
function of menisci
stabilize movement of round femoral condyles on flat tibial condyles = stabilize movement for femorotibial articulation
2 menisci in stifle
lateral
medial
stifle menisci: characteristics (2)
fibrocartilage discs
semilunar shape
6 ligaments that support the stifle
patellar
medial collateral
lateral collateral
caudal cruciate
cranial cruciate
meniscofemoral
patellar ligament/tendon
connect patella to tibia
medial collateral ligament
connect femur to tibia
lateral collateral ligament
connect femur to fibula
caudal cruciate ligament function
prevent CAUDAL slip of tibia
cranial cruciate ligament function
prevent CRANIAL slip of tibia
what do caudal and cranial cruciate ligaments do relative to each other
criss cross
meniscofemoral ligament
connect menisci to femur –> stabilize menisci
2 main movements at stifle
flexion
extension
in cats, the stifle has greater capacity for what 2 movements
translational mobility
rotation along long axis of tibia
what happens as stifle is flexed
lateral collateral ligament loosens –> allows internal rotation of tibia on femur –> cruciate ligaments twist on each other to limit this internal rotation
what happens as stifle is extended
lateral collateral ligaments tighten –> tibia rotates externally –> cruciate ligaments untwist (no limit on external rotation)
which cruciate ligament is more commonly torn
cranial
cause of CCL tear
sudden rotation of flexed stifle (slipping)
is a CCL tear more commonly acute or chronic
chronic
chronic cause of CCL tear
degenerative changes in ligaments
medial compartment of the stifle: 4 muscles, nerve, artery, action
sartorius, gracilis, adductor, pectineus
obturator artery
femoral nerve, obturator nerve
flex stifle
lateral compartment of the stifle: 3 muscles, innervation, action
biceps femoris, semitendinosus, semimembranosus
deep femoral artery
sciatic nerve
flex or extend stifle
cranial compartment of the stifle: 5 muscles, innervation, artery, action
quadriceps femoris = vastus medialis, vastus lateralis, vastus intermedius, rectus femoris
iliopsoas
femoral artery
femoral nerve
extend stifle
4 muscles of quadriceps femoris
rectus femoris
vastus medialis
vastus lateralis
vastus intermedius
muscle action of quadriceps femoris
extend stifle
muscle action of iliopsoas
flex hip
cranial part of sartorius action (stifle)
extend stifle
caudal part of sartorius action (Stifle)
flex stifle
gracilis action (stifle)
flex
semitendinosus action (stifle)
flex
what is the extensor group at the stifle
quadriceps femoris
origin of rectus femoris
ileum
quadriceps femoris: insertion, innervation
tibial tuberosity via patellar ligament
femoral nerve
specializations of horse stifle enable
horse can lock stifle when hindlimb is extended (save energy)
specialization of equine distal femur
enlarged medial epicondylar ridge
2 surfaces on equine trochlea
gliding
resting
what shape is equine patella
diamond
2 surfaces of equine patella
caudally facing surface
distally directed surface
caudally facing surface of equine patella engages
gliding surface of trochlea
distally directed surface of equine patella engages
resting surface of trochlea when in full extension
number of patellar ligaments: dog vs horse
dog = 2
horse = 3
3 patellar ligaments of horse
intermediate patellar
lateral patellar
medial patellar
3 other ligaments of equine stifle
medial femoropatellar
medial collateral
medial meniscus
what 3/6 STIFLE muscles are innervated by femoral nerve
iliopsoas
sartorius
quadriceps femoris = vastus medialis, vastus lateralis, vastus intermedius, rectus femoris
2 cutaneous branches off femoral nerve
caudal
lateral
function of saphenous nerve
sensory to medial leg and tarsus
effect of dysfunction of femoral nerve
paralyze quadriceps
stifle collapses = entire limb disabled
no compensation
no sensation on skin of medial surface of limb
locking mechanism of stifle
caudal facing surface of patella engages with gliding surface of trochlea (femur)
during resting position: medial patellar ligament runs even with edge of corresponding ridge of trochlea –> position maintained without assistance of quadriceps femoris –> this position is unstable so patella is easily dislodged BUT it slips back onto the gliding surface of the trochlea
origin of femoral nerve
L4-L6
where does femoral nerve enter thigh (between what 2 muscles)
sartorius and pectineus = femoral nerve